Polydimethylsiloxane (PDMS) is an inexpensive robust polymer that is commonly used as the fundamental fabrication material for soft-lithography-based microfluidic devices. Owing to its versatile material properties, there are some attempts to use PDMS as a porous 3D structure for sensing. However, reliable and easy fabrication has been challenging along with the inherent hydrophobic nature of PDMS hindering its use in biomedical sensing applications.
Researchers from the University of Michigan have developed a cleanroom-free inexpensive method to create 3D porous PDMS structures, “ExoSponge” and the effective surface modification to functionalize its 3D porous structure. The researchers demonstrate the ability of ExoSponge to recover cancer-associated extracellular vesicles (EVs) from complex biological samples of up to 10 mL in volume. When compared to ultracentrifugation, the ExoSponge showed a significant increase in cancer EV isolation of more than 210%. Targeted ultra-high pressure liquid chromatography-tandem mass spectrometry (LC-MS/MS) is further employed to profile 70 metabolites in the EVs recovered from the lung cancer patient’s plasma. The resulting profiles revealed the potential intraexosomal metabolite biomarker, phenylacetylglutamine (PAG), in non-small cell lung cancer. The high sensitivity, simple usage, and cost-effectiveness of the ExoSponge platform creates huge potential for rapid, economical and yet specific isolation of exosomes enabling future diagnostic applications of EVs in cancers.
Porous polydimethylsiloxane (PDMS) based cancer-associated extracellular vesicle isolation and recovery from body fluid samples